SETHI / RAMSES-NG: New performances of the flexible multi-spectral airborne remote sensing research platform

International audienceSETHI is an airborne SAR/GMTI system developed by the French Aerospace Lab. ONERA, and integrating various sensors. In 2016 ONERA invested in upgrade and improvement of all SETHI components. The microwave ones cover from VHF-UHF to X Band, full polarimetric and very high resolution, along track and cross track interferometry and very high precision multi-baseline capacity for interferometry and tomography applications. The optronic sensors offer very high spatial resolution visible images and fine spectral scene analysis in VNIR and SWIR bands. This paper presents the upgrade and new performances of this flexible platform and the qualification campaign results with various sensor configurations

Imagerie SAR haute résolution aéroportée

With the growing number of operating spatial systems, SAR imagery has become a major topic of research in the remote sensing community. In France, most of the research focuses on the exploitation of satellite SAR images. On the contrary, given the lower availability of such data, the airborne domain concerns a smaller community. This report aims at presenting the specificities of high-resolution airborne radar imagery and their impacts on multi-channel applications.A first part is devoted to a theoretical analysis of airborne SAR processing in its different modalities. The various SAR processing approaches adapted to high resolution are presented from a geometric point of view rather than frequential point of view. Then, the principles of multichannel processing are presented with emphasis on the phenomenology associated with the improvement of the resolution: link between image registration and interferometric phase, behavior of point like scatterers, anisotropic or surfacic backscatters. A second part is dedicated to the impact of real acquisition systems on SAR processing and multichannel applications. Issues related to the radar hardware, the antenna particularities, non-linearities of the trajectories are discussed and illustrated on applications such as calibration of polarimetric data, 3D extraction, ground moving target detection .Avec la multiplication des systèmes spatiaux, l’imagerie radar fait l’objet de nombreux travaux de recherche. En France, la majorité des travaux se concentre sur l’exploitation des images radar spatiales, de résolution de plus en plus fine. Le domaine aéroporté concerne une communauté plus restreinte étant donnée la moindre disponibilité de telles données. Ce rapport a pour vocation de présenter les spécificités de l’imagerie radar aéroportée haute résolution et d’en comprendre les impacts sur les applications multi-voies.Une première partie est consacrée à l’analyse théorique du traitement SAR aéroporté dans ses différentes modalités. Les diverses approches de traitement SAR adaptés à la haute résolution sont présentées selon un point de vue géométrique plutôt que fréquentiel. Puis, toujours sous ce même angle, les principes des traitements multivoies sont abordés en insistant sur les phénomènes apparaissant avec l’amélioration de la résolution : lien entre recalage d’images et phase interférométrique, comportement des rétrodiffuseurs ponctuels, surfaciques et anisotropes.Une deuxième partie est consacrée à l’étude de l’impact d’un système réel d’acquisition sur le traitement SAR et les applications multivoies. Les problématiques liées à la chaîne radar, aux diagrammes d’antennes, aux trajectoires non linéaires sont abordées.Enfin, différents travaux d’exploitation d’images radar haute résolution aéroportées (calibration de données polarimétriques, extraction du 3D sur les images SAR, détection de cibles mobiles) illustrent le propos

Matching Aerial Stereo Images Using Graduated Non Convexity Techniques

High resolution topographical data are used in many applications (urbanism, telecommunications ...). They include a Digital Elevation Model (DEM) of the scene and a description of man-made objects. They are usually derived from stereo images. The DEM is generally obtained from the disparity image which is computed using local correlations, whereas "man-made objects" are extracted by matching features (Michel, 1998). In this paper, we focus on the computation of disparity images from rectified stereo images. We consider that the disparity surface is a 3D surface which satisfies regularity constraints together with constraints specific to disparity and which has the smallest associated correlation cost. This surface is computed through the minimization of a cost-function which includes the above constraints. Because the optimization space of the cost function is particularly large (it corresponds to the number of pixels of the image) and because the cost function is multimodal and non-co..

Moving target tracking using circular SAR imagery

International audienc

Infection bactérienne materno-foetale du nouveau né à terme en région Poitou-Charentes (évaluation de l'incidence et des pratiques de prise en charge)

POITIERS-BU Médecine pharmacie (861942103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Performances analysis of moving target tracking in circular SAR

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Performances analysis of moving target tracking in circular SAR

International audienc

Moving target tracking using circular SAR imagery

International audienc

Airborne MIMO investigation for STAP-GMTI applications

International audienceGround moving target indicator (GMTI) radar performance is strongly depending on the antenna geometry: length of the equivalent radar aperture (longer apertures enable lower minimum detectable velocity-MDV) and sparsity. Compact and sparse multiple-input multiple-output (MIMO) techniques have been investigated into this paper to point out potential benefits compared to SIMO configuration. In 2016 an experiment was conducted with ONERA BUSARD motoglider to collect MIMO GMTI dataset on instrumented ground vehicles. DDMA waveform has been operated as orthogonal pattern on transmit. Analysis of the data indicates improved clutter nulling and resulting MDV with the MIMO techniques compared to the conventional SIMO one